The opposition in Belarus says four leading activists have been arrested by police in Minsk during a protest against the election result.
Opposition supporters defied police and braved sub-zero temperatures overnight, camping out in a central square. The crowd now numbers about 150.
The protesters accused President Alexander Lukashenko of rigging the vote and demanded fresh elections.
The EU and US have condemned the poll as flawed, but Russia says it was fair.
Results announced on Monday gave Mr Lukashenko victory with 82.6% of the vote.
The runner-up, Alexander Milinkevich, got just 6%, according to the official results.
Mr Milinkevich's campaign manager Anatoly Lebedko and three other top aides in his United Civil Party campaign team were arrested, Mr Milinkevich's spokesman said.
The other three were named as Alexander Dobrovolsky, Alexei Yanukiyevich and Valentina Pavelikova.
They were reportedly arrested as they returned to the rally after going to fetch food.
Protests began on Sunday evening as the polls closed, with some 10,000 people gathering in the capital's central October Square.
Thousands turned out again on Monday night, but numbers later dwindled to several hundred.
"Our protest will be strong and long," Mr Milinkevich told the crowd. "We will never recognise this election. It's not an election but an anti-constitutional seizure of power."
Opposition supporters defied police and braved sub-zero temperatures overnight, camping out in a central square. The crowd now numbers about 150.
The protesters accused President Alexander Lukashenko of rigging the vote and demanded fresh elections.
The EU and US have condemned the poll as flawed, but Russia says it was fair.
Results announced on Monday gave Mr Lukashenko victory with 82.6% of the vote.
The runner-up, Alexander Milinkevich, got just 6%, according to the official results.
Mr Milinkevich's campaign manager Anatoly Lebedko and three other top aides in his United Civil Party campaign team were arrested, Mr Milinkevich's spokesman said.
The other three were named as Alexander Dobrovolsky, Alexei Yanukiyevich and Valentina Pavelikova.
They were reportedly arrested as they returned to the rally after going to fetch food.
Protests began on Sunday evening as the polls closed, with some 10,000 people gathering in the capital's central October Square.
Thousands turned out again on Monday night, but numbers later dwindled to several hundred.
"Our protest will be strong and long," Mr Milinkevich told the crowd. "We will never recognise this election. It's not an election but an anti-constitutional seizure of power."
